Slush beverage machine



Sept. 10, 1968 J, BOOTH ET AL 3,400,551

SLUSH BEVERAGE MACHINE Filed June 28, 1967 3 Sheets-Sheet 1 INVENTORSJACK J. BOOTH WILLIAM C. BRANCH ATTORNEY FIG. I

Sept. 10, 1968 J. J, BOOTH ET AL 3,400,551

SLUSH BEVERAGE MACHINE Filed June 28, 1967 3 Sheets-Sheet 2 INVENTORSJACK J. BOOTH WILLIAM C. BRANCH FIG. 5 W

ATTORNEY Sept. 10, 1968 J. J. BOOTH ET AL SLUSH BEVERAGE MACHINE 5Sheets-Sheet 5 Filed June '28, 1967 FIG. 6

SYRUP-WATER MIXTURE TO- TANK l6 H m 5 m 0 B w c W cu. Mw

WATER ATTORNEY United States Patent 3,400,551 SLUSH BEVERAGE MACHINEJack J. Booth, 5006 Tanbark 75229, and William C. Branch, 6730 GreenwichLane 75230, both of Dallas, Tex.

Filed June 28, 1967, Ser. No. 649,541 11 Claims. (Cl. 62135) ABSTRACT OFTHE DISCLOSURE A slush bank is formed in a tank wherein liquidintroduced at the tank bottom is mixed with diffused carbona tion gasand frozen to slush under predetermined gas pressure while circulated byan impeller. Temperatures within the tank are maintained within a verynarrow range in order that a bank of slush is established and maintainedwith relatively low, energy transfer rates.

Field of the invention This invention relates to apparatus for producingslush beverages, .and more particularly to apparatus wherein liquid ismaintained under carbonation gas pressure during transfer of energythereto from a small-heat pump to form and maintain a slush bank.

Prior art Systems have heretofore been developed wherein carbonatedbeverages are maintained in tanks at pressures above atmosphericpressure and at temperature such that the carbonted beverage is notfrozen. When such a beverage is suddenly discharged into an area ofatmospheric pressure, a slushy beverage is provided due to expansion ofthe gas entrained therein. Illustrations of such systems may be found inUS. Patent No. 3,044,878 to Knedlik and US. Patent No. 3,108,449 toLents. Such systems have generally required refrigeration systems withrelatively large compressor units, and have often required continuousagitation and sensitive temperature control in order to prevent freezingof the beverage inside the pressurized tank. Further, heretoforedeveloped systems for producing slushy carbonated beverages have oftenrequired the introduction of excessive amounts of carbonated gas inorder to prevent freezing of the beverage inside the tank.

Summary In accordance with the present invention, a system is providedwherein a relatively small refrigeration compressor is employed incombination with a tank operated at generally low gas pressure toproduce a slushy beverage. A selected pressure is maintained on a liquidwhich is introduced into the bottom of a cylindrical tank and is mixedwith diffused carbonation gas. A refrigeration unit freezes the liquidto a slush bank, which is selectively dis- The drawings For a morecomplete understanding of the present invention and for further. objectsand advantages thereof, reference may now be had to the followingdescription taken in conjunction with the accompanying drawings inwhich:

FIGURE 1 is a somewhat diagrammatic view of a system according to thepresent invention;

FIGURE 2 is a view of a rotary impeller for use in the presentinvention;

FIGURE 3 is a view of a second embodiment of a rotary impeller for usein the present invention;

FIGURE 4 is a detailed view of a liquid mixing block for use in thepresent system;

FIGURE 5 is a sectional view taken generally along the section lines 55of FIGURE 1; and

FIGURE 6 is a schematic diagram of the present leve sensing system.

The preferred embodiments Referring to FIGURE 1, a slush beveragemachine designated generally by the numeral 10 includes a cylindricalmain body 12 having a top 14. A pressurized tank 16 is supported insidethe body 12 and surrounded by suitable insulating material 18. Thepressurized tank 16 includes a top member 20 which may be sealinglyattached and which includes a spring loaded relief valve 21. A nnumberof turns of cooling coils 22 are disposed about the outer circumferenceof the tank 16 and are connected to a suitable refrigeration unit 24.The cooling coils 22 are disposed about the lower half of the tank 16 toprovide greatest cooling in the bottom region of the tank. Therefrigeration unit 24 includes a compressor and the like, and isdisposed within a chamber formed in the main body 12 by a dividing wall26.

A dispensing spout 28 is located near the top of the tank 16 andincludes a manually operable knob 30 which may be actuated to dispense abeverage from tank '16. A similar spout 32 is disposed near the bottomof tank 16 and includes a manually operable knob 34 for selectivelydraining the contents of the tank when desired. Beverage liquid may beintroduced into the bottom of the tank 16 through the conduit 36 whichpasses through the bottom of spout 32. Conduit 36 is connected through asolenoid valve 38 to a mixing block 40, to be later described in detail.

The mixing block 40 mixes a supply of water, which is supplied through afilter 42 and a conduit 44, with a beverage syrup which is suppliedthrough the conduit 46 from the syrup supply tank 48. Syrup 49 in thesupply tank 48 is forced out through conduit 46 by pressure exerted bypressurized carbonation gas fed through conduit 50 from source 52. Aregulator valve 54 provides a relatively high pressure of carbonationgas to tank 48 to force syrup from tank 48 when the control valve isopened.

A continuous flow of lower pressure carbonation gas from the source 52is fed directly into the pressurized tank 16 through a regulator valve56 and a conduit 58. A check valve 59 is disposed near the end ofconduit 58. A porous bulb 60 is connected to the end of conduit 58 sothat carbonation gas is diffused into a plurality of pinpoint bubbleswhich are more easily absorbed by the beverage liquid in the bottom ofthe pressurized tank 16. The porous bulb 60 may be made from any one ofa plurality of suitable materials, such as porous stone, a porousplastic tube or the like. A temperature sensing element 61 is adjacentlydisposed to the porous bulb 60 in order to sense the temperature of thebeverage liquid in the bottom region of the pressurized tank 16.

A rotating impeller is provided inside tank 16 and includes a shaft 62journaled in suitable bearings in suitable bearings 64 for rotationthrough a connection 66 by an electric motor 68. Attached along thelength of shaft 62 and extending radially outwardly therefrom are aplurality of impeller vanes 70. As may be best seen in FIGURE 2, thevanes 70 have inclined flange portions of opposite slopes. Thus,rotation of the shaft 62 in the direction of the arrow 71 will cause thecarbonated beverage mixture inside the pressurized tank 16 to tend tocirculate upwardly in the center to the top regions of tank 16. A pairof parallel side bars 72 are connected to the ends of each of the vanes70. As shown in FIGURE 5, the bars 72 do not touch the side walls of thepressurized tank 16, but are disposed very closely thereto in order totend to remove any frozen particles from the region of the walls of tank16.

It is important in the practice of the invention to circulate the frozenparticles along the sides of tank 16 to an upper region of the tank toprovide a stratified slush bank near the dispenser spout 28. An impellerof the type shown in FIGURE 2, rotating at approximately 30 rpm. havingvanes 2.5 inches in width and inclined at 30, has been found to workwell in practice in combination with a 12 inch diameter pressurizedtank.

In operation, the pressurized tank 16 is filled with a predeterminedquantity of mixture of beverage, liquid, and water. Refrigeration isprovided through the coils 22 to the walls of the pressurized tank 16.The present device maintains a selected temperature, preferably between25 and 26.5 F., sufficient to freeze the portions of the beveragemixture in the region of the wall. Motor 68 continuously rotates thevanes 70 of the impeller inside the pressurized tank 16 to continuouslyremove the frozen particles, whereby the frozen particles tend to movealong the tank walls to the region of the dispenser spout 28 to form astratified slush band. Upon manual depression of the knob 30, the slushbeverage is dispensed through spout 28. It will be understood that whileFIGURE 1 illustrates movement of the frozen partices downwardly alongthe sides of the tank and upwardly through the center of the tank uponrotation of the impeller in the direction of arrow 71, that a suitablestratified slush bank could be formed in the upper regions of tank 16 byreverse rotation of the impeller. Such reverse rotation would causecirculation of the frozen particles downwardly through the middle of thetank and upwardly along the sides of the tank. The maintenance of anupper stratified slush bank enables a consistently uniform drink to bedispensed, even though a mixture of additional syrup and water is beingintroduced in the bottom regions of the tank. In some instances, theslush bank may build up and exist substantially throughout the length ofthe tank 16.

Carbonation gas under pressure from the source 54 is supplied throughthe syrup in the tank 48 and the mixing block 40, where the syrup ismixed in desired proportions with water. This mixture flows through theconduit 36 directly into the bottom of the pressurized tank 16.Carbonation gas under pressure is diffused throughout the bottom regionof the pressurized tank 16 through the porous bulb 60. The flow ofcarbonation gas diffused therethrough will be absorbed by the mixture inthe bottom regions of tank 16. The valve 21 located in top 20 of thetank 16 will open upon the advent of a pressure over a predeterminedmagnitude, which may preferably be about 22 p.s.i. The valve 21 servesto control the uniformity of the Brix, the Water to syrup ratio. Moreparticularly, when the material freezes it expands. This tends toincrease pressure. When pressure increases, less syrup flows into thetank, thereby decreasing the water to syrup ratio or the Brix, as it iswell known in the art.

By use of the valve 21, the variations in pressure in the tank areminimized so that the Brix will be held within limits which arepredetermined. Thus there results a more uniform product.

It will thus be understood that carbonation gas is being provided to thepresent system continuously through the porous bulb 60, with the mixtureof syrup and water being added to the tank 16 as needed. In practice,the pressure applied to the carbonation gas being supplied continuouslythrough the conduit 58 preferably is of the order of about 20 p.s.i.,while the pressure of the gas in conduit 50 will be of the highermagnitude of about 30 p.s.i. Because of the close control oftemperatures maintained in the tank 16 only a relatively smallcompressor is required in refrigeration unit 24. In practice, only a AHP compressor has been required, whereas prior units of similar beveragedispensing rate have required two horsepower units.

Referring again to FIGURE 1, electric power is supplied through lines 74and 75 from a suitable source of alternating current. The motor 68 isdirectly connected across the source of power by wires 76 and 77. Alevel control circuit 78 is connected through wire 81 to an elongatedelectrode 83 and through wire 85 to the case in order to provide aground.

The electrode 83 senses the level of the beverage in tank 16. When thelevel of the beverage drops to a level where electrode 83 no longercontacts the beverage liquid, a control circuit is actuated after apredetermined interval to open valve 38. More particularly, a suitableswitch is activated in the flow control circuit 80 to initiate fiow totank 16. As a result, a mixture of syrup and water flows from the mixingblock 40 through conduit 36 into tank 16. The level of the beverageinside the tank 16 will thus be raised.

When the fluid level inside tank 16 reaches the electrode 83, the switchin the control circuit is tripped to de-energize the solenoid 86 to stopthe flow of liquid to tank 16.

More particularly, a syrup sensor 88 is located in the conduit 46 tosense the flow of syrup through the conduit 46 when the relay 86 isactuated to open valve 38. When the syrup in supply tank 48 isexhausted, sensor 88 senses absence of liquid in conduit 46 and providescontrol over the solenoid 86 in order to cut off the flow of liquidthrough the conduit 36. This prevents the addition of only water fromconduit 44 to tank 16. When the syrup supply tank 48 is empty, a signallight 90 will indicate to the operator of the device that a new supplyof syrup needs to be provided.

An embodiment of the control circuit is shown diagrammatically in FIGURE6. Where consistent, like parts have been given the same referencecharacters as in FIG- URE 1. Line 74 and 75 supply electrical power totwo similar circuits 78 and 80. The circuit 78 serves to controlsolenoid 86 in response to the presence or absence of liquid on theprobe 82 which is mounted in the lid 20. The circuit 80 controls theapplication of power to a relay depending upon the presence or absenceof syrup in the sensor 88.

The circuit 78 includes a line 131 extending from line 75 to oneterminal of solenoid 86. Line 132 extends from line 75 by way of a solidstate switching device 133 and thence by way of a relay control switch134 to the second terminal of the solenoid 86. The device is a triacdevice, conductive bidirectionally when suitably actuated by a controlvoltage applied thereto. The triac may be of the type manufactured andsold by RCA as Triac No. 40526. In accordance with the presentinvention, a control circuit is provided for the triac 133. A delay isintroduced after the liquid level recedes below the probe 83 beforeactuating the solenoid 86. More particularly, a resistor 136 connectsthe line 131 to the lid 20 or to another suitable ground terminal. Probe83 is connected to line 132 by way of a capacitor 137. Probe 83 is alsoconnected to one terminal of a neon discharge tube 138. The secondterminal of the tube 138 is connected to the gate terminal of a siliconcontrolled rectifier 139. A suitable unit for rectifier 139 would be ofthe type manufactured and sold by General Electric Company as SCR-C106-B2. The cathode of the rectifier 139 is connected to conductor 132.The anode is connected by way of resistor 140 to line 131. The gateterminal is connected to terminal 132 by way of resistor 141.

A control condenser 142 is connected in series with resistor 143 andrectifier 144, the series circuit thus found being connected betweenlines 131 and 132. The juncture between condenser 142 and resistor 143is connected to the anode of the rectifier 139 and to one terminal of aneon discharge tube 145. The other terminal of tube 145 is connected tothe gate terminal of the triac 133.

In operation, the condenser 142 is charged at a rate dependent upon thetime constant of the series circuit and thus primarily upon the relativevalues of resistor 143 and condenser 142. In operation, condenser 142begins charging through rectifier 144. When the condenser voltagereaches a value to fire the tube 145, the triac 133 begins to conduct.When triac 133 conducts, the solenoid 86 is energized to open valve 38thereby causing flow of syrup-water mixture through tube 36 to tank 16.When the liquid level in the tank rises such that it touches the bottomof the probe 83, the capacitance in the circuit of the discharge tube138 is such that the rectifier 139 will be fired. This dischargescondenser 142. Thereafter rectifier 139 conducts on each cycle of thealternating current voltage applied thereto. The condenser 142 will bemaintained substantially discharged. Thus, as long as the liquid is incontact with the probe 83, there will be no conduction through the triac133 and the valve 38 will remain closed.

In accordance with the present invention, the time constant of thefiring circuit for the triac 133 is of several seconds duration. In oneembodiment, the resistor 143 was 15,000 ohms and the condenser 142 was50 microfarads. The presence of resistor 140 assures positive turnoff ofrectifier 139 upon reversal of the AC. potential thereacross and placesa negative potential on the rectifier 139 so that it cannot conduct. Theresistor 136 is relatively high so that the lid 20 will not be at anysubstantial A.C. potential. In a preferred embodiment, the time constantof the circuit 78 is such that the valve 38 will open three to 'fiveseconds after the liquid level recedes below probe 83.

The circuit 80 is similar to that of circuit 78 in most respects exceptthat the time constant of the circuit, including the resistor 150 at thecondenser 151 may be much shorter, and in some instances may beeliminated. However, in this case, the circuit is responsive to thepresence or absence of syrup in the sensor 88. When no syrup is present,the triac 152 is fired to energize relay 130. Relay 130 controls theswitch 134 and a second switch 154. The switch 134 is in theenergization circuit for the valve solenoid 86. The switch 154 isconnected in the circuit for a signal lamp 155. Lamp 155 is energizedwhen the syrup supply is exhausted. The opening of switch 134accompanies the closing of switch 154 to prevent flow of water to thetank 16. An operator, in response to energization of lamp 155, will thenreplenish the supply of syrup. When this is completed, a push button 160may be actuated mechanically to reclose the switch 134, thereby openingthe valve 38 to initiate flow. The push button 160 will be depressedmanually until such time as the syrup flows in the sensor 88. Thiscondition will have been achieved when, upon release of the button 160,the light 155 remains de-energized.

By reason of the control thus afforded and by reason of the presence ofthe control valve 21, there may be variations in level and character ofmaterial in tank 16 without materially affecting the Brix thereof. Thusthe system may be maintained in operation substantially entirelyautomatically while assuring constancy in the quality of the product.

A control circuit for the operation of the refrigeration unit 24 is alsoprovided in the present invention. The

, temperature sensitive device 61 is connected through cable 92 to asuitable switch 94 which may provide either an open or closed circuitbetween the power lines 74 and 75 in order to control the operation ofthe refrigeration unit 24. In the position of the switch 94, illustratedin FIG- URE 1, the temperature of the liquid in tank 16 is such thatrefrigeration is required. Switch 94 thus has a completed circuitbetween the power lines 74 and 75 in order to cause operation of therefrigeration circuitry 24. When the temperature sensitive device 61provides an indication that a sufficiently low temperature has beenprovided, the switch 94 will open the circuit between the power lines 74and 75 in order to stop the operation of the refrigeration circuitry 24.

FIGURE 3 illustrates a second embodiment of a rotary impeller for use inthe present invention, wherein each vaneradially extending from theshaft 62 includes two inclined flange portions 98 and 100 which slant inopposite directions. The particular configuration of the rotary impellershown in FIGURE 3 causes, upon rotation of the impeller in the directionof arrow 102, the frozen particles near the side walls of tank 16 to bedislodged and moved toward the center region of the tank. The sideportions 72 in combination with the inclined flange portions 100 act tomove the frozen particles from the tank side walls and downward alongthe tank walls. The rotating action of the inclined flange portions 98in the center region of tank 16 causes the frozen particles to moveupward in the center portion of the tank 16, thus maintaining a fairlyuniform two-phase mixture throughout tank 16.

FIGURE 4 illustrates in detail the construction of the mixing block 40which includes a first inlet 104 having a ridged portion 106 adapted tobe connected to receive water through the conduit 44 (FIGURE 1). A checkvalve disposed in inlet 104 includes a ball valve member 108 which isupwardly biased by a spring 110 in order to allow only a one-way flowthrough inlet 104. The rate of flow of Water is controlled by a flowcontrol washer 111 which maintains a constant flow rate over the rangeof pressures normally encountered in city water lines, i.e., a flow rateof from A to A: gallon per minute, where pressures range from 30 p.s.i.to 1 00 p.s.i.

A second inlet 112 includes a n'dged portion 114 for connection to theconduit 46 through which syrup is supplied. A ball valve 116 is upwardlybiased by a spring 118 in order to provide a check valve to preventbackfiow through the inlet 112. An outlet 120 is perpendicularlyprovided through the rectangular mixing block 40 to the inlets 104 and112 and opens into a ridged nozzle 122 for connection to conduit 36(FIGURE 1). A screw 124 is threadedly received in one end of the outlet120 and includes a projection 126 which may be disposed between theopening of the inlet 112 into outlet 120. The position of projection 126controls the amount of syrup which is mixed with the water Suppliedthrough the inlet 104. By retraction of the screw 124, the projection126 will be moved away from the inlet 112, thereby allowing a greateramount of syrup to be mixed with the water. If desired, a control washersimilar to washer 111 may be utilized to control the flow of syrup inplace of the screw 124. In such case, the flow of syrup would beregulated to approximately /5 the flow allowed in the water inlet.

It will thus be understood that the present invention provides a slushmachine wherein relatively low carbonation pressure is normallyemployed, in combination with relatively low power refrigeratingcomponents, in order to freeze portions of the liquid inside thepressurized tank to establish and maintain a Stratified slush bank inthe upper regions of the tank. Improved contact of carbonation gas andthe liquid inside the pressurized tank is obtained through theutilization of a porous bulb. Circuitry is provided to selectivelycontrol the operation of the refrigerating unit, in addition to controlof the introduction of additional beverage into the unit whilemaintaining within predetermined limits the syrup-water ratio.

Whereas the present specification has been described in considerabledetail with respect to preferred embodiments of the present invention,it is to 'be understood that this description is for purposes ofillustration, and that changes or variations may be made by personsskilled in the art without departing from the scope of this invention ras set forth in the appended claims.

What is claimed is:

1. In a system for producing a slushy drink, the combination whichcomprises:

(a) a vertically disposed cylindrical tank having walls and an inlet forreceiving liquid in the bottom therein and having an outlet port nearthe top,

(b) means for introducing carbonation gas under pressure into said tanknear the region of said inlet for absorption by said liquid,

(0) means for maintaining said gas in said tank above atmosphericpressure,

(d) refrigeration means including coils disposed about said tank forfreezing said liquid to slush,

(e) impeller means having vanes so inclined and rotatable in said tankto circulate said liquid with said carbonation gas downward along thewalls of said tank and upward in the center of said tank to maintain astratified slush bank in at least the upper regions of said tank, and

(f) temperature sensor for sensing liquid temperature and controllingsaid refrigeration means to maintain said slush bank of frozen particleswithin a selected narrow temperature range at and slightly below thefreezing point of water at the pressure within said tank.

2. The combination defined in claim 1 and further comprising a levelcontrol means for introducing additional liquid into said cylindricaltank upon withdrawal of a portion of said slush bank of frozen particlesthrough said outlet port and a pressure relief valve in said tank forlimiting the pressure in said tank to maintain substantially constantthe syrup-water ratio in the presence of changes in quantity andcharacter of the contents of said tank.

3. The combination defined in claim 1 wherein all means for introducingcarbonation gas comprises:

a permeable diffusion chamber disposed near the region of said inlet fordividing gas flow into a plurality of pinpoint bubble streams throughsaid liquid for absorption thereby.

4. The combination defined in claim 3 wherein said diffusion meanscomprises:

a bulb having a fixed orifice and porous outer walls disposed in theregion of said inlet,

conduit means connecting said fixed orifice of said bulb to a source ofcarbonation gas,

whereby pinpoint bubble streams of the carbonation gas will diffusethrough said porous outer walls into said liquid.

5. The combination defined in claim 1 wherein said impeller meanscomprises:

a rotatable shaft disposed generally along the longitudinal axis of saidtank,

a plurality of vanes laterally extending from two sides of said shaftand each having inclined flange por- 50 tions to move frozen particlesfrom the region of the walls of said tank along the walls of said tank.

6. The combination defined in claim 1 and further comprising a pressurerelief valve disposed through the upper portion of said cylindrical tankfor venting the pressure in said tank when the pressure increases abovea predetermined magnitude to control the syrup-water ratio in said tank.

7. The combination of claim 1 and further comprising:

means for providing a supply of syrup to said inlet of said cylindricaltank, and

means responsive to the absence of syrup in the flow line leading intosaid tank for terminating the supply of water when the supply of syrupis exhausted.

8. The combination defined in claim 1 and further comprising:

(a) a supply of beverage liquid,

(b) means for providing two supplies of carbonation gas under differentpressures, one of said supplies being fed directly into the bottom ofsaid tank, and

(c) means for feeding the other of said supplies of carbonation gas toforce said liquid supply into the bottom of said tank.

9. The combination defined in claim 1 and further comprising:

(a) a first inlet for connection to a supply of beverage liquid such assyrup,

(b) a second inlet for connection to a water supply,

(c) one-way valves disposed in each of said inlets for allowing liquidflow in only one direction, and

(d) an outlet communicating with both of said inlets and said tank.

10. The combination defined in claim 9 and further comprising fiowcontrol means interposed in at least one of said inlets for controllingthe amount of liquid flow therethrough.

11. The combination defined in claim 10 wherein said first and secondinlets extend parallel from one side of a mixing block, and wherein saidoutlet extends through said block perpendicularly to said inlets whilecommunicating with the same, and

said flow control means includes means disposed in said outlet andadjustable to control the flow path in said outlet between said firstinlet and said second inlet.

References Cited UNITED STATES PATENTS 1,519,746 12/1924 Valerius 62-69X 2,134,787 11/1938 Hartman 6270 2,531,315 11/1950 Wyllie 62--306 X2,849,868 9/1958 Anderson 62342 3,004,398 10/1961 Mullins 62342 X3,180,110 4/1965 Dunn 62354 X 3,240,395 3/1966 Carver 62390 X ROBERT A.OLEARY, Primary Examiner.

W. E. WAYNER, Assistant Examiner.

